Katter's Australian Party says if it comes to power at the federal election, it will allow irrigators to take more water from the Murray-Darling Basin.

Launching its policy on the basin, the party also says it will return South Australia's Lower Lakes to an estuarine system - a mix of salt and fresh water.

Chair of the South Australian branch of the party, Glenn O'Rourke, says he doesn't believe this would have a big impact on bird and fish life.

"The lower lakes was originally an estuarine system. It already still does, depending on the weather conditions, and the water flows and winds and all sorts of things like that, it already still operates as a semi-estuarine system while they're trying to maintain it at freshwater levels."